pam_get_user man page

The pam_get_user function returns the name of the user specified by pam_start(3). If no user was specified it what pam_get_item (pamh, PAM_USER, ... ); would have returned. If this is NULL it obtains the username via the pam_conv(3) mechanism, it prompts the user with the first non-NULL string in the following list:

· The prompt argument passed to the function.

· What is returned by pam_get_item (pamh, PAM_USER_PROMPT, ... );

· The default prompt: "login: "

By whatever means the username is obtained, a pointer to it is returned as the contents of *user. Note, this memory should not be free()'d or modified by the module.